Method of and apparatus for the magnetic separation of materials



March 17, 1925. 4 1,529,970

G. ULLRICH METHOD OF AND APPARATUS FOR THE MAGNETIC SEPARATION OF MATERIALS Eiled July 15, 1923 2 Sheets-Sheet 1 Much 17, 1925. I 1,529,970

G. ULLRICH METHOD OF AND APPARATUS FOR THE MAGNETIC SEPARATION OF MATERIALS Filed July 13, 1923 2 Sheets-Sheet 2 Patented Mar. 17, 1925.

GEORG ULLRICH, OF MAG-DEBURG, GERMA NY, ASSIGNOR TO THE FIRM FRIED. KRUPP AKTIENGESELLSCHAFT, GRUSONWERK, F MAGDEIBURG-BUGKAU, GERMANY.

METHOD or AND ArrAnArus ron THE MAGNETIC sErAnA'rIoN or MATERIALS.

Application filed July 13, 1923. Serial at. 651,369.

.use more and more on account of their low cost of manufacture and upkeep, but in respect of the efliciency of their separation they have hitherto been inferior to ring separators. In order to be able, as in ring separators, to operate on more than one kind of raw material in one separator plant or to increase the capacity of the separator plant for raw material of one kind by the simultaneously multiple supply of raw material or the subsequent separation of magnetic and non-magnetic material, it has hitherto been necessary to employ either two or more separators or toarrange a plurality of magnetic systems alongside each other in a single separator. Either the provision of a plurality of drum separators or the arrangement of a plurality of magnetic systems alongside .each other considerably augments the cost of manufacture and upkeep of the plant.

The object of the present invention is to provide a method of separation for drum separators, by means of which method, without materially increasing the said costs, two or more kinds of raw material can be treated on a single drum separator, or in cases where only one kind of raw material is being separated the output of the separator may be increased. This object is attained by delivering material to the same annular sepa rating path of a drum at different points on its circumference and diverting, taking oil or throwing oil the magnetic material from this separating path between every two of these points of separation.

Raw material of the same or different kinds can be treated at the various'points where it is separated. Magnetic material, which has been obtained at one of the separating points and then removedfrom the separation path can also'be delivered again to the said path by another material delivering apworking a subsequent separation of the'non-magnetic' material may also be provided for.

Both drum se arators with fixed magnetic systems and rotating drums and those with rotating magnetic systems and fixed drums may be employed for carrying out the new method.

In the first case there are provided on the circumference of an annular path on the drum and behind each other two or more separation fields or zones of a single field and between every two separation fields or zones an interruption in the field that is to say a feebly magnetic or non-magnetic zone.

Each separation field or zone is provided with means for delivering the material and each interruption of the field with means for catching themagnetic material. The several separating fields or zones may be of equal or of difierent strengths and each may increase or decrease in strength in the well known manner. If a magnetic system be employed which forms only a single annular field interrupted or weakened at the point where the magnetic material is taken off, the magnetic system may be so attached to the separator shaft that its position can be altered by rotation. Such a magnetic system may also be divided into separate magnets and these latter may be pivotally mounted on the separator shaft independently of each other. The separating zones or fields may then be adjusted as regards their relative positions.

In the second case that is tosay where a separator with rotating magnetic system and a stationary drum are em loyed, two or. more arrangements for dellvering the material alternate in the circumference of a closed annular field with a like number of deflecting devices for the magnetic material.

By the new method it is possible to build cheap and eflicient separators which are capable of considerably augmenting the range of use of the magnetic separation. As i an example of their use the separation of In the preparation of ores aconsiderable increase in the .elficiency of the apparatus is secured by the new method without any material increase in the cost of working and installing expenses. If for example the magnetic material obtained at one point of separation and immediately afterwards thrown ofi from the separating surface or carried oif therefrom be again delivered to the next point of separation of the same annular separating path, the new method is particularly suitable for theseparation of different kinds and degree of fineness but one or more. of these fields may also be used simultaneously or solely for a further subsequent separation of themagnetic or nonmagnetic material falling into an adjacent field from a main separation. The material to be so subsequently separated is then simply passed over into the adjacent field to the desired point. Instead of surrounding suchindependent magnetic fields. with a common drum as in drums may be divided and the several parts of the drum may be given diiferent speeds.

The apparatus for delivering the material or mixture of materials may be so arranged that the material is -graded thereon into grains of difi'erentsizes in the well known way. a

It will be pbvious fi om the ego-ing that the new method possesses, in addition to the advantages of simplicity and cheapness, that also of an extended possibility of use an manifold possible form of construction. It is also obvious that additional devices may be employed for the improvement of the delivery and separation, for example vibratory delivery devices, purifying jets, etc.

'In the drawing a number of examples for carrying out the method forming the subject matter of the present invention are shown.

Figures 1, 2 and 4 each show a drum separator with a stationarymagnetic system and a rotating drum, with different methods of working, a Figures 1 and 4 being cross sections, and Figure 2 a longitudinal section of Figure 1.

Figure 3 shows a drum separator in which a magnetic system rotates inside a stationary drum. V r 1 I In Figures 1 to 4 are shown separators in which magnetic material separated atone drum separators the point of separation is delivered again by the material delivering apparatus at the next point of separation on the same annular path for subsequent separation, after which it is thrown off or removed from the annularpath between the two material delivering points.

According to the constructional form shown in Figures 1 and 2 there is mounted on the shaft 18 of the drum 19 which rotates in the direction of the arrow :0 a magnetic system 20 which forms by means of the two annular poles 21 and 22 an annular mag netic field. This magnetic field has two zones of separation 23 and 24, a weakly magnetic zone 25 and a weak magnetic or non-magnetic zone 26. The material is delivered by the delivery apparatus 27 and passes over the deflector 28 (preferably adjustable) into the main separating zone 23. At this point the magnetic material is attracted to the drum 19. The non-magnetic material can either be conducted directly into the receptacle 30 or as shown and for the purpose of subsequent separation on to a seconddelivery apparatus 29 similar to the first which brings it into the field again. The field may at this point be stronger than at the first point of separation. The magnetic material travels with the rotating drum upwards and passes to the weakly magnetic zone25 where it is thrown off from the rotating drum against a baflie plate 31. While the magnetic material is thus thrown ofi the drum and against the battle plate any non-magnetic material still associated there with or adhering thereto is separated from the former. Both kinds of material are then again delivered by means of the delivery apparatus 32 to the annular path of separation in the zone 24 of the same magnetic field. The non-magneticunaterial falling-away may as in the first zone of sepad ration be conducted for the purpose of a subsequent separation by a second delivery apparatus to the zone 24 again. It then falls into he receptacle 34. The magnetic ,materal attracted in the zorie 24 to the drum 19 then finallyfdrops from the drum. at the. non-magnetic zone 26 and is received"in the receptacle 35. I

According to the constructional form shown in Figure 3 the magnetic system 37 rotates about a shaft 36 which may conveniently be provided on its periphery with teeth 38 or similar devices. The raw ma-' terial, for example-magnetite sludge; is delivered by the delivery apparatus 40. The non-magnetic material is delivered, after having been subsequently separated, into the. receptacle rotating magnets the magnetic material travels upwards with a rolling movement on the stationary drum 39. This rolling movement assists the separation of the magnetic 41. Under the influence of the v guiding device 43 into the same magnetic field for the purpose of being subsequently separated again on the drum. While the non-magnetic material, after subsequent separation if necessary, falls into the receptacle 44 the magnetic material continues'to travel on the drum andis finally removed from the field into the receptacle 46 by means of a guiding apparatus 45.

- In the separator shown in Figure 4 the new method of separation is employed conjointly withone already \known according to which a mixture of material is graded into two degrees of fineness b the delivery device and these two sizes of material delivered to a cylindrical separator with the coarser kind above the finer. As the delivery apparatus lies on the side of the cy- Iindrical or drum separator on which the direction of the path of the drum or cylinder which forms the separating surface is upwards, the fine magnetic material attracted travels with the drum upwards and passes through the zone of separation of the coarse raw ,material. The stream of fine magnetic material unites therefore with the coarse magnetic material on the drum. Both kinds of magnetic material are then con-. jointly carried downwards by the revolving drum and fall oif at the lower part-of the path of the drum.

Although the separate separation of fine and coarse materials securesa greater purity of the magnetic material obtained it does happen nevertheless that non-magnetic materlal remains associated with the magnetic or adheres to it. For this reason it is advisable in many cases to separate the magnetic material obtained over again. For this purpose it has been necessary in the methods hithertb known either to deliver the mixture of fine and coarse magnetic material to a second separator or if only a single separator be employed to interrupt the delivery of the raw material for some time and during this time to subsequently separate the magnetic material on the same separator. The first method requires increased installation and working costs and the second diminishes the output of the separator.

These disadvantages are overcome by the use of the new method which constitutes the present invention. This is' accomplished in the following manner.

. The raw material is first delivered in different sizes of grain, each size of grain separately, to a cylindrical separating surface and the magnetic material separated atall the points of delivery combined on the separating surface. After it has been combined the whole of the magnetic material is removed from orthrown off the annular separating path and soon returned toit' again at the next separating pointin the same annular path. magnetic material is conveyed to the lower part of the separator. The removal from the .drum may be effected in any desired manner. The magnetic material may for example be thrown off at a weakly magnetic or a non-magnetic zone. the raw material and the subsequent separation of the combined magnetic material may take place in two independent fields of the separator or in two zones of equal or different strength of a single field.

The construction of the separator shown by way of example in Figure 4 is as follows i About a stationary magnetic system 47 rotates a drum 48 in the direction of the arrow 00. The magnetic system forms a single circular magnetic field with two.zones of separation 49 and 50 and two weekly magnetic or non-magnetic zones 51 and 52. The raw material falls on to the sieve 54 of the vibratory delivery apparatus 53. The coarse material travels over this sieve and passes over a deflector 55 (preferably adjustable) to the drum 48 in the upper part of its path. It passes then into the precincts of the zone (or of the'field) 49. The nonmagnetic material falls away and is caught in the chute 56. The coarse magnetic material travels with the drumin the direction of the arrow w. The fine raw material falls through the sieve 54 on to the surface of the table 57 and travels over this latter and the "deflector 58 to the same drum and into the same zone under the coarse material. "The non-magnetic material falls into the receptacle 59 after having been subsequently separa'tedin the same zone by means of the deflector 60 which is preferably adjustable. The fine magnetic material travels with the rotating drum upwards in the zone of separation of the coarse material. It is then thrown off (after passing through this zone) together with the coarse magnetic material after it has entered the weakly magnetic zone 51 which begins preferably at the highest point of the drum. The magnetic material is caught by a delivery apparatus 61 separation of the annular path of separation and into the precincts of the zone 50.

Finally the subsequently separated The separation of which again conveys it to the next point of points of separation-and also at the points of removal of the products from the drum after subsequent separation.

The apparatus" for delivering, conveying away and catching the different kinds of material and also the baflie plate 31 (Fig ures 1 and 4) maybe arranged adjustably.

It is of particular advantage in all the constructional forms and also economical to provide a single field with two or more zones ,of separation as shown but two or more separate fields may be provided.

The method may be used for dry as well as for wet materials.

Having now particularly described and ascertained the nature of the said invention, and in what manner the same is to be performed, as communicated to me by my foreign correspondents, I declare that what I claim is z- 1. The process of magnetic separation by a drum separator, consisting infirst subjecting the material to be separated to a plural ity of separating actions on one portion of the drum, removing the material thus gathered on the drum surface, and re-delivering it to another portion of the drum Where it is again subjected to a separating action. i

2. The process of magnetic se aration by a drum separator, consisting in rst subjecting the material to be separated to a plurality of separatingactions on one portion of the drum, removingthe material thus gathered on the drumsurface, and re-delivering it to another portion of the drum where it is again subjected to a plurality of separating actions. g I

3. The process of magnetic separation by a drum separator, consisting in delivering the material to be-separated at a plurality of points on the drum surface, removing at a common point the material thus gathered on the drum surface, and re-delivering the removed material as a whole to another portion of the drum surface.

4. In a magnetic drum separator, means for initially subjecting the material to be separated to a plurality of separating actions on one portion of the drum surface,

means for removing the material thus gathmeans for removing the material thus gathered on the drum surface, and means for re-delivering the -removed material'to another portion of the drum surface and there subjecting it to a plurality of separating actions.

6. In a magnetic separator of the rotating drum type, stationary ring poles within the drum and in substantially symmetrical circumferential relation therewith, the annular field of said poles being divided into alternate relatively weak and strong portions, and drum-cooperating delivering and intercepting means for the material to be separated at said strong and weak field portions respectively. f

'7, In a magnetic separator of the drum type, a magnet system whereby a closed annular path of separation is formed on the drum, and a plurality of delivering and intercepting means for alternatelydelivering the material to be separated into said annular path and intercepting it therefrom.

8. In a magnetic separator of the drum type, a rotating magnetic system within the drum whereby an annular path of separation is formed on the drum, and a plurality of g delivering and intercepting means for alternately delivering the material to be separated into said annular path and intercepting it therefrom.

In testimony whereof the foregoing specification is signedin the presence of two witnesses.

Witnesses:

ANNA SGHAFER, Wnmm Fmiscmamox.

GEORGVULLRIOH. 

